The apthous lesion, or canker sore, as it is commonly known, is a painful oral ulcer which exists in connection with a disease known as apthous stomatitis. The cause of this disease is essentially unknown, and truly effective treatment for curing same and/or relieving the discomfort of same has not been established until conception of the present invention.
Many etiologic factors have been suggested as causing apthous ulcerations. Heredity has been suggested as one; and although there is no evidence of genetic origin in the disease, apthous lesions have been frequently observed in several members of the same family. The disease has sometimes been thought to be viral; and although Herpes simplex ulcers often appear to be similar in appearance to the apthous ulcer, there is no evidence that this virus (Herpes) is the etiologic factor in apthous stomatitis. Tissue cultures have been uniformly negative in identifying Herpes simplex in apthous lesions. Bacterial factors (bacillus crassus) have frequently been thought to be the cause of canker sores; but no one bacterial agent has ever been found to be consistently associated with apthous ulcerations, and there is no evidence of cross-infection. Protoza has sometimes been suggested as a cause of this disease, but no conclusive evidence has ever been established that this is so.
While it is strongly suspected that trauma may contribute to the development of the apthous lesion, it is not considered to be the sole cause. Most likely the tissue was sensitized and made susceptible to the apthous lesion by a traumatic injury. However, it has been observed that a traumatic injury does not result in canker sores in many cases, and particularly in connection with those people not prone to develop such lesions. Another observation is that the eruption of apthous lesions is frequently associated with the onset of menstruation and has also been correlated with post-menopausal women. It has further been observed that recurrent apthae completely subside during pregnancy in otherwise highly susceptible women. Regardless of this apparent hormonal relationship, there is no definite explanation of the mechanism of this phenomenon. Add to this the fact that apthae are frequently seen in men, and the roll of hormones in this disease becomes even more suspect.
There have been numerous reports in the literature of apthous outbreaks following the ingestion of certain drugs or foods. There is, however, little evidence that these eruptions are due to hypersensitive reactions; although some observers feel that hypersensitivity helps to support the reaction. It has also been noted that with apthous ulcers, as with many other kinds of ulcers, acute psychologic factors appear to precipitate attacks of the disease. Although such psychological factors are difficult to analyze, it nevertheless has been popularly concluded that mental stress and psychological disturbances act as a precipitating mechanism to the disease, although they cannot be considered as the actual cause.
Gastrointestinal factors have also been thought to have some relationship to apthous lesions. In a test that was conducted on 120 patients afficted with such lesions, it was found that 41% had dyspepsia, and 9% showed demonstrable peptic ulcerations. It is frequently difficult to separate gastrointestinal disturbance from psychosomatic factors. The gastrointestinal tract is extremely susceptible to emotional disturbances, and lesions of the stomach and lower intestinal tract, coexistent with apthous stomatitis, could be of psychosomatic origin. In fact, the psychosomatic cause of gastric ulcer is well established.
Turning now to the clinical appearance of apthous ulcers, it has been noted that they are single, multiple, round or oval ulcerations. They range in size from 2 to 40 mm. in diameter, and they occur on mucous membrances of the tongue, cheek, lips, soft and hard palates, gingiva, pharynx, and the floor of the mouth. These lesions are also found in the genital, anal, and in conjunctival mucosae. Apthae are extremely painful lesions. They first appear as a small macular red lesion. These areas quickly undergo necrosis, leaving a sharply defined, rounded ulcer, usually varying from 2 to 5 mm. in diameter. The ulceration is fairly deep, with a yellow-white base representing necrotic tissue at the surface. The margins of the ulcer are somewhat indurated, and the marginal mucosa has a surrounding erythamatous zone. The marginal erythema ranges from slight to extensive, depending upon the degree of secondary bacterial involvement. The ulcer is present for approximately seven days, and it undergoes gradual healing. It heals, as a general rule, in approximately ten to fourteen days, and usually leaves no scarring.
Characteristically, there is a recurrent pattern of one or more of these ulcers. The lesions may reoccur as often as one month apart; and there are cases where for a period of years the individual is never without apthous lesions, new ones forming as the previous ones heal. In other cases, apthous attacks may occur two to three times during a year. The lesions often appear following some intense emotional stress, but they may first appear following a gradual change in environment or following an emotional situation, such as the early adjustment period of marriage, boarding school, new employment in a nonfamiliar environment, etc. Apthous sores have been found to occur in cyclic patterns in females. They may appear several days prior to the menstrual period. The first encounter with apthous stomatitis may follow the onset of menstruation. Women susceptible to this lesion often report freedom from the lesions during pregnancy. There is a tendency for a greater frequency of these lesions in females than in males; and although apthae occur at any age level, they seem to occur more often in young adults. The term "periadenitis mucosa necrotica recurrens" is sometimes used to describe large apthae that coalesce to form an elongated, deep ulcerated area.
From a symptomatic standpoint, it has been found that approximately 24 to 48 hours prior to the onset of an apthous lesion there is a vague discomfort, sometimes described as a tingling sensation, in the area. As the tissues undergo necrosis and an ulcer forms, the lesion becomes very painful. The apthous lesions are often considered to be the most painful of oral ulcerative lesions. The discomfort may become particularly intense during periods of fatigue.
Turning to the histopathology of the disease, it has been found that the microscopic picture thereof is non-specific, generally showing an ulceration of the mucosa. The surface epithelium exhibits a central area of destruction. The connective tissue is densely infiltrated with lymphocytes, polymorphonuclear leukocytes, plasma cells, and histocytes. There is evidence of active fibrosis at the base and sides of the ulcerated area.
Differential diagnosis may include traumatic ulcer, acute herpetic stomatitis, stomatitis medicamentosa, and erythema multiforme. The diagnosis of apthous stomatitits is based upon the clinical manifestations and the patient's history. Biopsis are usually unnecessary and, due to the extreme discomfort involved, are avoided unless necessary to rule out other lesions considered in the differential diagnosis.
Many different substances and agents have heretofore been used in an attempt to cure and/or relieve the discomfort of apthous lesions. For example, cauterizing drugs (escharotic agents), such as phenol, chromic acid, alum and silver nitrate, have been used for many years. These agents alleviate pain by destruction of the small nerve endings. The healing time of the lesion is prolonged due to the escharotic action of these drugs on the surface epithelium and the active fibrosis at the base and sides of the ulcerated areas. Different vitamins have been tried, with inconsistent results; and various antibiotics have also been used, with conflicting results. One observer found that aureomycin applied locally (250 mg. in 10 ml. of water) three times a day appeared to have a definite effect. The duration of the ulcers was reduced from approximately ten to five days, and there was an analgesic effect lasting one-half to two hours. Temporary relief has also been sought, and sometimes achieved, by using milk of magnesia, or various heavy syrups. The transient nature of their benefits renders these preparations impractical. More recently, mucuous membrance adhering compounds ("Orabase", Squibb trademark) have become available to eliminate irritants that delay healing. Other more exotic remedies have been tried with little or no success, such as vaccination with cowpox virus, lactobacillus containing materials, and nutrient supplements.
Corticosteroid agents have also been used in several ways for the treatment of aphtous stomatitis. These agents possess anti-inflammatory properties and have been successful in suppressing or reducing inflammatory processes in the skin and mucous membranes. It has been found that topical applications directly to the apthous lesions avoid the systemic effect of corticosteroid. Topical applications are therefore preferred to the systemic route, especially if long-term treatment is anticipated, since even though some absorption occurs with topical steroids, it is never enough to be of real concern. Topical cortisones used for apthous lesions include hydrocortisone, prednisolone, and dexamethasone. These agents must be frequently and thoroughly applied to the ulcers in ointment or cream form. Corticosteroids, such as triamcinolone, have been incorporated into a base, such as "Orabase", which has the property of adhering to mucous membrane. It is thought, however, that very little, if any, of the active medication is released from the heavy paste so as to be effective.
Attempts have been made to use intralesional injection to treat apthous lesions, this method concentrating the drug at the lesion, while usually avoiding significant systemic effects. The problem with this treatment, however, is that significant discomfort may be present, especially if the apthous lesions are numerous. In addition, patients with gastric ulcers may absorb enough steroid to complicate and aggravate their gastric ulcer.
In situations where patients have numerous lesions and, as a result, topical therapy is unsatisfactory due to the number of ulcers and their inaccessibility, attempts have been made to use systemic treatment. This form of treatment may result in severe complications, particularly with ulcer patients. It should only be used in very severe cases when it is essential that the patient not be incapacitated. Daily dosage of injections of corticosteroids must be gradually reduced. It is hazardous to suddenly stop systemic cortisone administrations, and this treatment should be avoided entirely where gastric ulcers are present.
It will therefore be seen that none of these prior approaches have proven altogether successful in the treatment of canker sores, since none of them quickly cure the condition, and since many of them create other complications.
It is therefore a primary objective of this invention to provide a quick, convenient, safe and relatively painless method of treating apthous lesions, commonly known as canker sores.
Other objects, features and advantages of the invention will become apparent as the description thereof proceeds.